1,798,096 research outputs found
A Crevice on the Crane Beach: Finite-Degree Predicates
First-order logic (FO) over words is shown to be equiexpressive with FO
equipped with a restricted set of numerical predicates, namely the order, a
binary predicate MSB, and the finite-degree predicates: FO[Arb] = FO[<,
MSB, Fin].
The Crane Beach Property (CBP), introduced more than a decade ago, is true of
a logic if all the expressible languages admitting a neutral letter are
regular.
Although it is known that FO[Arb] does not have the CBP, it is shown here
that the (strong form of the) CBP holds for both FO[<, Fin] and FO[<, MSB].
Thus FO[<, Fin] exhibits a form of locality and the CBP, and can still express
a wide variety of languages, while being one simple predicate away from the
expressive power of FO[Arb]. The counting ability of FO[<, Fin] is studied as
an application.Comment: Submitte
FO(FD): Extending classical logic with rule-based fixpoint definitions
We introduce fixpoint definitions, a rule-based reformulation of fixpoint
constructs. The logic FO(FD), an extension of classical logic with fixpoint
definitions, is defined. We illustrate the relation between FO(FD) and FO(ID),
which is developed as an integration of two knowledge representation paradigms.
The satisfiability problem for FO(FD) is investigated by first reducing FO(FD)
to difference logic and then using solvers for difference logic. These
reductions are evaluated in the computation of models for FO(FD) theories
representing fairness conditions and we provide potential applications of
FO(FD).Comment: Presented at ICLP 2010. 16 pages, 1 figur
Covariant description of kinetic freeze out through a finite space-like layer
The problem of Freeze Out (FO) in relativistic heavy ion reactions is
addressed. We develop and analyze an idealized one-dimensional model of FO in a
finite layer, based on the covariant FO probability. The resulting post FO
phase-space distributions are discussed for different FO probabilities and
layer thicknesses.Comment: 16 pages, 19 figures, changed content, references adde
Covariant description of kinetic freeze out through a finite time-like layer
The Freeze Out (FO) problem is addressed for a covariant FO probability and a
finite FO layer with a time-like normal vector continuing the line of studies
introduced in Ref. [1]. The resulting post FO momentum distribution functions
are presented and discussed. We show that in general the post FO distributions
are non-thermal and asymmetric distributions even for time-like FO situations.Comment: 10 pages, 12 figures, major rewrite with changed content, corrected
typos and new references adde
Freeze out of the expanding system
The freeze out (FO) of the expanding systems, created in relativistic heavy
ion collisions, is discussed. We start with kinetic FO model, which realizes
complete physical FO in a layer of given thickness, and then combine our
gradual FO equations with Bjorken type system expansion into a unified model.
We shall see that the basic FO features, pointed out in the earlier works, are
not smeared out by the expansion.Comment: 3 pages, 2 figure
Leading particles and diffractive spectra in the Interacting Gluon Model
We discuss the leading particle spectra and diffractive mass spectra from the
novel point of view, namely by treating them as particular examples of the
general energy flow phenomena taking place in the multiparticle production
processes. We argue that they show a high degree of universality what allows
for their simple description in terms of the Interacting Gluon Model developed
by us some time ago.Comment: Presented at Diffraction2002, Alushta, Crimea (Ukraina), August 31 -
September 5, 2002. To be published by Kluwer Academic Publishers (2003)
(necessary style files attached). Rewritten according to the Kluwer
specification
Active adjustment of the cervical spine during pitch production compensates for shape: The ArtiVarK study
The anterior lordosis of the cervical spine is thought to contribute to pitch (fo) production by influencing cricoid rotation as a function of larynx height. This study examines the matter of inter-individual variation in cervical spine shape and whether this has an influence on how fo is produced along increasing or decreasing scales, using the ArtiVarK dataset, which contains real-time MRI pitch production data. We find that the cervical spine actively participates in fo production, but the amount of displacement depends on individual shape. In general, anterior spine motion (tending toward cervical lordosis) occurs for low fo, while posterior movement (tending towards cervical kyphosis) occurs for high fo
Exploring the differences between forward osmosis and reverse osmosis fouling
A comparison of alginate fouling in forward osmosis (FO) with that in reverse osmosis (RO) was made. A key experimental finding, corroborated by membrane autopsies, was that FO is essentially more prone to fouling than RO, which is opposite to a common claim in the literature where deductions on fouling are often based solely on the water flux profiles. Our theoretical analysis shows that, due to a decrease in the intensity of internal concentration polarization (ICP), and thus an increase in the effective osmotic driving force during FO fouling tests, the similarity of experimental water flux profiles for FO and RO is in accordance with there being greater fouling in FO than RO. The specific foulant resistance for FO was also found to be greater than that for RO. Possible explanations are discussed and these include the influence of reverse solute diffusion from draw solution. Whilst this explanation regarding specific foulant resistance is dependent on the draw solution properties, the finding of greater overall foulant accumulation in FO is considered to be a general finding. Additionally, the present study did not find evidence that hydraulic pressure in RO plays a critical role in foulant layer compaction. Overall this study demonstrated that although FO has higher fouling propensity, it offers superior water flux stability against fouling. For certain practical applications this resilience may be important
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